The covert eavesdropping of the MP Sadiq Khan is alleged to be just the first case in a far wider operation to bug terrorist suspects and other serious criminals introduced after the September 11 attacks.
Lawyers, including the human rights solicitors Gareth Peirce and Mudassar Arani, were allegedly "routinely bugged" by police during visits to see clients at Woodhill prison. Listening devices were said to have been concealed in tables at the jail.
Nationally it is thought that many more people may have been covertly recorded.
The scandal came to light after Mr Khan, a Muslim Labour MP, was covertly recorded during two visits to a terrorist suspect held at Woodhill prison in Milton Keynes in 2005 and 2006.
It led to a political outcry as the bugging of MPs has been prohibited since the 1960s. Mr Straw was forced to set up an inquiry. He insisted he had known nothing of the operation before last weekend, although it later emerged that officials in his department had learnt of the allegations two months ago.
Now someone with detailed knowledge of the operation claims that Mr Khan's visits were allegedly among "hundreds of conversations" bugged by Det Sgt Mark Kearney during his time with a four-man intelligence team based at the prison since early 2002.
The recordings are deemed so sensitive that copies are stored at a secret facility protected by armed guards.
Initially, only a handful of prisons implemented the alleged bugging policy - including Woodhill and Belmarsh - but over the past 18 months the secret policy is alleged to have been rolled out across Britain.
it's not just the UK, of course - here in the US we also have the fight over FISA. On one side we have the Constitution and our rule of law, and on the other we have those who would tear those thing asunder for the sake of "security". They hate our freedoms, indeed.